In a scenario wherein after the sched_scan_start there is a system
recovery and previous pending sched_scan request is lost and during
the sched_scan_stop driver is returning error.
Because of which __cfg80211_stop_sched_scan will not
clear “rdev->sched_scan_req” blocking further sched_scan requests.
Return success in the event that the driver does not have any pending
sched scan to flush.
Change-Id: I6aba88ce033c59ebae54ca792e241a17b649ad73
CRs-Fixed: 2340653
2131523a2b